Metal furniture and process for making same



METAL FURNITURE AND PROCESS FOR MAKING SAME Filed July 7, 1960 M. GOLDMAN Nov. 6, 1962 2 Sheets-Sheet 1 INVENTOR. "o f/s GOLD/14 Nov. 6, 1962 M. GOLDMAN 3,062,571

METAL FURNITURE AND PROCESS FOR MAKING SAME Filed July 7, 1960 2 Sheets-Sheet 2 INVENTOR. Ma a 5 A rraw/srs United States Patent 3,062,571 METAL FURNITURE AND PROCESS FOR MAKING SAME Morris Goldman, RD. 3, Quakertown, Pa. Filed July 7, 1960, Ser. No. 41,419 1 Claim. (Cl. 28754) This invention relates to metal furniture of the kind having metal legs, leg braces, and the like, fully exposed to view when the furniture is in use.

The metal stock from which such furniture is made may be provided with various decorative surface finishes. For example, aluminum, brass, stainless steel and other metals and may have their surfaces polished to a mirror finish, provided with a satin finish, anodized, painted or coated with plastics, or otherwise made more attractive.

Industrial designers favor such stock when made with a rectangular cross-sectional shape. Where transverse members join, such as in the case of a table leg and a cross leg brace for example, these designers prefer that the parts meet in a correspondingly rectangular manner. They want all of the surfaces to have the desired finish throughout. Joints incorporating rivets, brazing or welding, socket members, and the like, are considered to be objectionable because of the consequent defacement of the stocks surface or because the transversely meeting surfaces cannot be made with sharply rectangular corners, or for both reasons.

An object of this invention is to reduce the cost of making such metal furniture while providing the above stated industrial design features. Another object is to make metal furniture having sharp-cornered frame joints, in a fashion reducing the cost of applying the desired finish to the surfaces of the metal parts. Another object is to reduce the shipping cost of metal furniture. Other objects may be inferred from the following.

Specific examples of the invention are illustrated by the accompanying drawings in which: v

FIG. 1 is a perspective view of a table incorporating the invention; 7

FIG. 2 is avertical section taken on the line 2--2 in FIG. 1; i

FIG. 3 is a vertical section taken on the line 33 in FIG. 2;

FIG. 4 is a vertical section taken on the line 4-4 in FIG. 3 and shows an assembly step;

FIG. 5 is a partly sectioned perspective view of the parts as shown by FIG. 4;

FIG. 6 is a side view showing another form of the invention;

FIG .7 is a topview of FIG. 6;

FIG. 8 is a side view of a third form of the invention; and j FIG. 9 is a top view'of FIG. 8. v v

The tableillustrated by FIG. 1 is of modern design having four vertical legs 1, transverse horizontal leg braces 2 and longitudinal and horizontal leg braces 3. The table top 4 is a fiat piece of heavy transparentglass. The legs and their braces are all of rectangular cross section, are made ofmetal in all instances, and are fully exposed to view. ,The necessary joints between the legs and leg braces provide sharply rectangular corners in all instances. The means by which the joints are fastened together are completely invisible and any surface finish previously applied to the various metal members is completely unmarred and unchanged throughout all exposed surfaces including the joints.

The appearance of this table is free from the commercial look associated with prior art metal furniture using joints which are brazed or Welded, riveted, fastened by visible socket members, and the like. The metal parts may be made of any suitable metal and provided with any desired surface finish, as previously indicated. Fur-' niture of this kind is suitable for any use.

The manner in Which the joints are made without marring the previously applied surface finish and with the fastening means invisible is revealed by FIGS. 2 and 3. Here it can be seen that the legs 1 are made from hollow stock and that at each joint the legs sidewall has a slot formed in it in the form of a keyhole. The large upper portion 5 of this slot is concealed by the upper portion of the brace 3 and the latter is made from solid stock and cut to form a tongue 6 having vertical grooves 7 formed in its sidewalls and dimensioned for a press fit with the hollow stocks side edges defining the smaller portion 8 of the keyhole. The width of the solid stock 3 defined by its grooved sidewalls is great enough to laterally conceal even the large portion 5 of the keyhole and the vertical dimension of the solid stock forming the brace 3 which is the width of this stock, is great enough to conceal the top and bottom of the keyhole. This width is at least as great as the length of the keyhole shaped slot.

Note that the thickness of the solid stock is substantially equal to the corresponding inside dimension of the hollow stock, that the length of the tongue 6 is proportioned to'bring its end face 6a into flat abutting relation with the corresponding inside of the hollow stock forming the leg 1 and that the tongue is not reduced in thickness. The groove 7 is joined at the bottom of the tongue by a transverse groove 7a which receives the bottom edge of the small part 8 of the keyhole, in this form of the invention, this requiring a slot length a little less than the solid members Width. I

The manner of assembly is shown by FIGS. 4 and 5 wherein the tongue 6 has been passed longitudinally through the large part 5 of the keyhole slot. The groove male parts are dimensioned'for a press fit with the female parts. Using a suitable tool the brace 3 is pressed downwardly to form the press fit. The tongue itself should not fit the inside of the leg 1 so tightly as to deform the latter in an externally visible manner. The slot portion 8 is made with straight sides to fit with the solid bar.

According to this invention the desired finish is applied to all of the surfacesprior to the assembly described above. At this time all ofthe parts are simply straight sections and therefore automatic mechanical or chemical processing of allkinds may be used as required to provide the finish desired. The surfaces may be finished prior to milling or otherwise forming the joint shapes because the latter may be made without affecting a previously applied finish. Standard lengths of standard rectangular metal stock may be given any surface finish desired and then made into the desired metal furniture without affecting the finish visibly. Surface finishing of any kind is done at any time prior to assembling the joints. 1 In making the joint the solid bar is grooved at a location providing a length beyond the grooves which substan tially equals the corresponding inside dimensions of thehollow members. This brings the solid bars end surface in contact with the corresponding wall of the hollow part to increase the rigidity of the joint. The solid part has a width between its grooved walls causing a corresponding bracing action with the inside of the hollow part.

The joint used by this invention is entirely mechanical. In this way the stock may first be completely surface finished, the joints then formed without affecting this finish and the parts then later put together to produce furniture ready for all normal use.

The table shown by FIG. 1 is illustrative of only one of the many furniture possibilities made commercially possible by the present invention. Other table designs, chairs, and other articles of furniture may now be made of rectangularly cross-sectional stock using invisible joints having sharp rectangular corners at the joints. The ultimate surface finish desired is in all cases applied prior to assembly of the furniture. This previously applied finish is not marred in any way by making the joint or by its mode of assembly.

FIG. 6 shows the invention applied in the case of a simpler joint. Here a vertical member 9 is made from rectangular metal tubing and is provided with a vertical slot 10 extending downwardly from the open upper end of the part 9. The other part or member 11 has two grooves 12 formed transversely in its sides 13 which conceal the slot because the width of the solid member 11 is greater than that of the slot 10. This forms the tongue 14 which is simply a continuation of the solid bar 11, and with the thickness of the latter equaling the inside corresponding dimension of the rectangular tube 9, and with the location of the grooves 12 such that the length of the tongue 14 equals the corresponding inside dimension of the part 9, the tongue 14 is closely embraced on all of its vertical sides by the inside of the rectangular tube 9.

Here again the finish may be applied at any time prior to cutting or milling the parts and thereafter the two members 9 and 11 may then be press fitted together to form a joint of the character previously described.

In some instances three members must meet with two of the members in the same plane. Such an instance is illustrated by FIGS. 8 and 9.

In this case the rectangular metal tube 15 is formed with two slots 16 and 17 in an adjacent two of its walls. One solid bar 18 is provided with the previously described grooves 19 defining a tongue 20 that differs from that previously described by having a width less than the corresponding inside dimension of the part 15. This leaves room for the tongue 21 of a bar 22 corresponding to the rectangular bar 18 and having corresponding grooves 23.

The above may be called a double joint. The tongue 20 is braced on its end and one vertical side by the inside of the rectangular tube 15, while its other vertical side is braced by the end of the tongue 21, one side of this tongue 21 also being braced by the inside of the tube 15. To provide greater rigidity both bars 18 and 22 may be provided with bottom grooves corresponding to the groove 7a previously described and of which one is shown by FIG. 8, this being the groove 19a which functions to join the two grooves 19.

It is to be noted that in all cases the vertical sides at least of the tongues formed by the ends of the solid bars, are of rectangular contour so as to nest snugly within the hollow rectangular member. In all cases, the joint is integrated by the press fitting of the grooves of the tongues or solid members in the slots formed in the rectangular tubular or hollow members. The press fits may be made tight enough to assure permanently interfastened joints when the furniture is subjected to all normal use.

In some instances only the grooves may be press fitted in the slots. However, greater strength is obtained by making the tongues the same dimensions as the hollow parts within which the tongues nest. Even greater strength results from making the tongues slightly oversize providing the hollow parts are not thereby visibly expanded after the press fitting of the parts.

This invention also permits finished furniture to be shipped less expensively because the furniture may be shipped unassembled or partly assembled to conserve shipping space. Special tools are not required for its assembly. Thus the furniture may be assembled easily at the place where it is to be used.

In the following claim it is to be understood that in addition to the metal parts defined the metal furniture in some instances may include non-metallic parts as previously indicated.

I claim:

Metal furniture having at least one double joint formed by three mutually transverse metal members of rectangular cross-section, said first member being made from hollow stock of rectangular cross-section and having a first slot and a second slot respectively formed in each of two adjacent sides of said first member at the joint location, a second member being made of solid stock of rectangular cross-section and having sides defining a width that is greater than the width of said first slot, said sides of said second member having transverse grooves formed therein adjacent to one end of said second member and the edges of said hollow stock of said first member defining said first slot being received by and press fitted with said grooves of said first member, portions of said solid stock of said second member defining said grooves abutting the slotted side of said hollow stock of said first member and concealing said first slot, the portion of said second member beyond said grooves and inside of said hollow stock of said first member having a fiat end abutting the inside surface of said first member adjacent thereto and at least one fiat side abutting the inside surface of said first member adjacent thereto, and a third member made from solid stock of rectangular cross-section and having sides defining a width that is greater than said second slot, said sides of said third member having transverse grooves formed therein adjacent to one end of said third member and the edges of said hollow stock of said first member defining said second slot being received by and press fitted with said grooves of said 'first member, portions of said solid stock of said third member defining said grooves of said third member abutting the adjacent side of said first member having said second slot and concealing said second slot, the portion of said third member beyond its said grooves and inside of said first member, having a flat end abutting the flat side of said second member adjacent thereto and at least one fiat side abutting the inside surface of said first member adjacent thereto such that said first hollow member and said second and said third solid members form a rigid common joint.

References Cited in the file of this patent UNITED STATES PATENTS 

